style.css

@import url('https://fonts.googleapis.com/css2?family=Poppins&display=swap');

*, *::after, *::before {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

.root {
    background-color: #121818;
    min-height: 100vh;
    padding-top: 1px;
    font-family: "Poppins", sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    flex-direction: column;
}

.title {
    color: #fff;
    text-align: center;
    font-size: 40px;
}

.image {
    color: #fff;
    display: flex;
    justify-content: center;
    align-items: center;
}

.image img {
    width: 50px;
    height: 50px;
}

.display {
    color: #fff;
    font-size: 25px;
    text-align: center;
    margin-top: 1em;
    margin-bottom: 1em;
}

.hide {
    display: none;
}

.container {
    margin: 0 auto;
    display: grid;
    grid-template-columns: 33% 33% 33%;
    grid-template-rows: 33% 33% 33%;
    max-width: 300px;
}

.tile {
    border: 1px solid #fff;
    min-width: 100px;
    min-height: 100px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 50px;
    cursor: pointer;
}

.playerX {
    color: #09c372;
}

.playerY {
    color: #498afb;
}

.controls {
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
    margin-top: 1em;
}

.ironMan {
    background: url(icons/ironman.png) center center no-repeat;
    background-size: cover;
}
.captain {
    background: url(icons/shield.png) center center no-repeat;
    background-size: cover;
}

#reset {
    cursor: pointer;
    padding: 0.6em 1.8em;
    border-radius: 5px;
    outline: none;
    border: none;
    font-size: 1.1rem;
    margin-top: 10px;
}